Abstract
This paper presents a multi-axial magnetorheological (MMR) mount. The MMR mount has been developed with the intent for use in hybrid vehicles. Hybrid vehicles come with additional inherent vibration due to the power mode switching. There are many classifications for vibration, but for the purpose of this study, the harmonic excitation over a wide range of frequencies will be discussed. This vibration can be classified as having large displacement at low frequency and small displacement at high frequency. This means that there is a contradiction of requirements: a stiff mount for the low frequency response and a soft mount for the high frequency response. With an MMR mount, damping and stiffness can be altered to yield acceptable dynamic stiffness for the frequency range of concern. This is achieved through the use of multiple inertia tracks paired with a MR fluid technology. Additionally, the proposed mount is semi-active, so there is inherent stability to the mount. The MMR mount uses elastomer and MR fluid. Through the use of this combination, high static stiffness to support the payload and low dynamic stiffness to isolate vibration can be realized. There are many advantages when using an MMR mount. They are as follows: fewer mounts are required, stability when compared to an active mount, less power required when compared to an active mount, better isolation when compared to pure elastomeric and passive hydraulic mounts. A model for an MMR mount has been mathematically developed and simulated in the MATLAB/Simulink® environment. For the purposes of this study, elastomer has been considered to have a linear dynamic response. Future work includes a finite element (FE) and computational fluid dynamics (CFD) simulation and manufacturing of an MMR mount to verify the simulation results.
Keywords: Vibration Isolation, Magnetorheological Fluids, Multi-directional excitation